JP2012032323A - Picture measuring device, picture measuring method and program for picture measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture measuring device capable of both identifying errors along edge positions of a work and readily grasping a relationship of correspondence to a work picture.SOLUTION: A picture measuring device comprises: edge extracting means that extracts edges from a work picture; measurement setting data memory means that holds measurement setting data including contour information on the work and an allowance of contour positions; error calculating means that aligns the positions of the work picture and the contour information and calculates errors indicating amounts of displacement between the edge positions on the work picture and contour positions corresponding to these edge positions; error determining means that compares the calculated errors with the allowance and determines whether or not the errors are acceptable; and measured result displaying means that displays the extracted edges and the result of determination on the work picture. The measured result displaying means numerically displays, regarding any edge position whose error has been determined to be unacceptable, errors of the edge position where the error magnitude is at its maximum.

Description

  The present invention relates to an image measurement apparatus, an image measurement method, and a program for the image measurement apparatus, and more particularly to an image measurement apparatus that measures the dimensions of a workpiece by detecting an edge in the workpiece image obtained by photographing the workpiece. .

  In general, an image measuring apparatus is an apparatus that measures a dimension of a workpiece by acquiring a workpiece image obtained by photographing the workpiece and detecting an edge in the workpiece image (for example, Patent Documents 1 to 3). Usually, the workpiece is placed on a movable stage movable in the X, Y and Z axis directions. The workpiece image is focused by moving the movable stage in the Z-axis direction, and the position of the workpiece in the field of view is adjusted by moving in the X- and Y-axis directions.

  The workpiece image is a very accurate similar shape to the workpiece regardless of the position of the movable stage in the Z-axis direction, so the actual dimensions on the workpiece are detected by determining the distance and angle on the image. can do. In measuring the dimensions of a workpiece, edge extraction of the workpiece image is performed. Edge extraction is performed by analyzing the brightness change of the workpiece image to detect edge points, and by fitting geometric shapes such as straight lines and arcs to the detected edge points, for example, An edge indicating the boundary is obtained. Alternatively, when the contour shape of the workpiece is a complicated shape, the workpiece contour information created using CAD (Computer Aided Design) and the edge point group extracted from the workpiece image are directly compared. Thus, an error indicating the degree of deviation of the edge position is measured.

  Some conventional image measurement apparatuses display edge points extracted from a work image along contour positions created by CAD. If the edge points extracted from the workpiece image are displayed along the contour position, it is possible to easily grasp how much the workpiece contour is deviated from the design value, but the correspondence between the edge points and the workpiece image I couldn't figure out the relationship. In general, with optical measuring instruments, edge points are mistakenly extracted when dust or dirt adheres to the measurement object, lighting is improperly applied, or there are scratches on the stage. It can be considered that. In such a case, if the error can be identified along the edge position of the workpiece and the correspondence between the error and the edge position where the error is outside the tolerance range can be grasped, whether the workpiece is actually deformed, or Therefore, it is possible to easily determine whether the edge point is erroneously extracted.

JP 2009-300124 A JP 2009-300125 A JP 2010-19667 A

  The present invention has been made in view of the above circumstances, and is an image measuring device that can identify an error along the edge position of a workpiece and can easily grasp the correspondence with the workpiece image. An object is to provide a program for an image measurement method and an image measurement apparatus. In particular, an object of the present invention is to provide an image measuring apparatus that can easily identify an error of an edge position that greatly deviates from a design value among edge positions where the error is outside the tolerance range.

  An image measuring apparatus according to a first aspect of the present invention is an image measuring apparatus that measures a dimension of a workpiece by acquiring a workpiece image obtained by photographing the workpiece and detecting an edge in the workpiece image. Edge extracting means for extracting an edge from the image, measurement setting data storage means for holding measurement setting data including contour information and contour position tolerance of the workpiece, the workpiece image and the contour information are aligned, and the workpiece image An error calculating means for calculating an error indicating an amount of displacement between the upper edge position and the contour position corresponding to the edge position; an error determining means for comparing the calculated error with the tolerance and performing a pass / fail determination; A measurement result display means for displaying the extracted edge and the result of the pass / fail judgment on the work image, wherein the measurement result display means has a poor error. For the determined edge positions adapted to numerically display the error of the edge position the magnitude of the error is maximum.

  According to such a configuration, when the result of error determination is displayed on the work image, the error at the edge position where the error is maximized is displayed numerically for the edge position where the error is determined to be defective. Therefore, the error of the edge position greatly deviating from the design value among the edge positions where the error is outside the tolerance range can be easily identified. In addition, since the edges extracted from the work image are displayed on the work image together with the error pass / fail judgment result, the error can be identified along the edge position of the work and the correspondence with the work image can be easily grasped. can do.

  In addition to the above-described configuration, the image measurement apparatus according to the second aspect of the present invention is configured so that the measurement result display means has an edge position at which the magnitude of the error is maximum in a certain section including a region where the error is outside the tolerance range. The error is numerically displayed as the representative value. According to such a configuration, it is possible to easily identify the error of the edge position that deviates most from the design value within a certain section on the edge.

  In addition to the above-described configuration, the image measurement apparatus according to the third aspect of the present invention is configured such that the measurement result display means displays a numerical value of an error in association with an edge position where the magnitude of the error is maximum. According to such a configuration, an edge position greatly deviating from the design value can be easily identified.

  In addition to the above configuration, the image measurement apparatus according to the fourth aspect of the present invention is configured such that the measurement result display means displays a tolerance range including the contour position on the workpiece image. According to such a configuration, it is possible to easily grasp how much the contour of the workpiece is deviated from the design value or whether the edge position is within the tolerance range.

  An image measuring apparatus according to a fifth aspect of the present invention includes, in addition to the above-described configuration, connected image generation means for connecting two or more captured images obtained by capturing different parts of the same workpiece and generating one workpiece image. Composed. According to such a configuration, when the field of view is narrow with respect to the workpiece to be measured, the edge position error can be identified for a wide range of the workpiece without reducing the photographing magnification, and the workpiece image Can be easily grasped.

  An image measurement method according to a sixth aspect of the present invention is an image measurement method for measuring a dimension of the workpiece by acquiring a workpiece image obtained by photographing the workpiece and detecting an edge in the workpiece image. An edge extraction step for extracting an edge from the image, a measurement setting data storage step for storing measurement setting data including the contour information of the workpiece and tolerances of the contour position, the workpiece image and the contour information are aligned, and the workpiece image is aligned An error calculating step for calculating an error indicating an amount of displacement between the upper edge position and the contour position corresponding to the edge position; an error determining step for comparing the calculated error with the tolerance and performing a pass / fail determination; The extracted edge and the result of the quality determination are displayed on the work image, and the error is determined at the edge position determined to be defective. There are, and a measurement result display step of numerically displaying the error of the edge position the magnitude of the error is maximum.

  A program for an image measuring device according to a seventh aspect of the present invention is a program for an image measuring device for measuring a workpiece size by acquiring a workpiece image obtained by photographing a workpiece and detecting an edge in the workpiece image. An edge extraction procedure for extracting an edge from the workpiece image, a measurement setting data storage procedure for storing measurement setting data including tolerance information of the workpiece and contour position, and the workpiece image and the contour information. , And an error calculation procedure for calculating an error indicating an amount of displacement between the edge position on the workpiece image and the contour position corresponding to the edge position, and comparing the calculated error with the tolerance. The error determination procedure for performing the determination, the extracted edge and the result of the quality determination are displayed on the work image, and the error is determined to be defective. The edge positions, to execute a measurement result display procedure for numerically displaying the error of the edge position the magnitude of the error is maximum.

  In the image measuring apparatus, the image measuring method, and the program for the image measuring apparatus according to the present invention, when the result of the error determination is displayed on the work image, the size of the error is determined for the edge position where the error is determined to be defective. Since the error of the edge position where the maximum value of the error is displayed numerically, the error of the edge position greatly deviating from the design value can be easily identified among the edge positions where the error is outside the tolerance range. In addition, since the edges extracted from the work image are displayed on the work image together with the error pass / fail judgment result, the error can be identified along the edge position of the work and the correspondence with the work image can be easily grasped. can do.

It is the perspective view which showed one structural example of the image measuring apparatus 100 by embodiment of this invention. FIG. 2 is an explanatory diagram schematically showing a configuration example in the measurement unit 10 in the image measurement apparatus 100 of FIG. 1, and shows a state of a cut surface by a vertical surface of the measurement unit 10. 3 is a flowchart illustrating an example of the operation of the image measurement apparatus 100 in FIG. 1. 3 is a flowchart illustrating an example of an operation when creating measurement setting data in the image measurement apparatus 100 of FIG. 1. 3 is a flowchart illustrating an example of an operation at the time of measurement in the image measurement apparatus 100 in FIG. 1. 3 is a flowchart showing an example of an operation at the time of displaying a pass / fail judgment result in the image measuring apparatus 100 of FIG. It is the figure which showed an example of the operation | movement at the time of the display of the quality determination result in the image measuring apparatus 100 of FIG. 1, and the workpiece | work image 1 which caught the mode of the whole workpiece | work is shown. It is the figure which showed an example of the operation | movement at the time of the display of the quality determination result in the image measuring apparatus 100 of FIG. 1, and the workpiece | work image 1 which captured a part of workpiece | work of FIG. 7 is shown. It is the figure which showed another example of the operation | movement at the time of the display of the quality determination result in the image measurement apparatus of FIG. FIG. 2 is a block diagram illustrating a configuration example of a control unit 20 in the image measurement apparatus 100 of FIG. 1, in which an example of a functional configuration in the control unit 20 is illustrated.

<Image measuring device>
FIG. 1 is a perspective view showing a configuration example of an image measuring apparatus 100 according to an embodiment of the present invention. The image measuring apparatus 100 is a measuring instrument that photographs a plurality of workpieces arranged in a detection area 13 on a movable stage 12 at different imaging magnifications, analyzes the captured images, and automatically measures the dimensions of each workpiece. , Measuring unit 10, control unit 20, keyboard 31 and mouse 32. The workpiece is a measurement object whose shape and dimensions are measured.

  The measurement unit 10 is an optical system unit that irradiates a workpiece with detection light and receives the transmitted light or reflected light to generate a photographed image. The display unit 11, the movable stage 12, the XY position adjustment knob 14a, and the Z position adjustment. A knob 14b, a power switch 15 and a measurement start switch 16 are provided.

  The display 11 is a display device that displays captured images and measurement results on the display screen 11a. The movable stage 12 is a mounting table for mounting a workpiece to be measured, and is provided with a detection area 13 that transmits detection light. The detection area 13 is a circular area made of transparent glass. The movable stage 12 can be moved in the Z-axis direction parallel to the optical axis of the detection light and the XY axial directions perpendicular to the optical axis.

  The XY position adjustment knob 14a is an operation unit for moving the movable stage 12 in the X-axis direction and the Y-axis direction. The Z position adjustment knob 14b is an operation unit for moving the movable stage 12 in the Z-axis direction. The power switch 15 is an operation unit for turning on the power of the measurement unit 10 and the control unit 20, and the measurement start switch 16 is an operation unit for starting measurement on the workpiece.

  The control unit 20 is a controller that controls photographing and screen display by the measurement unit 10 and analyzes the photographed image to measure the dimensions of the workpiece, and is connected to a keyboard 31 and a mouse 32. After the power is turned on, if a plurality of works are appropriately arranged in the detection area 13 and the measurement start switch 16 is operated, the dimensions of each work are automatically measured.

<Measurement unit>
FIG. 2 is an explanatory diagram schematically showing a configuration example in the measurement unit 10 in the image measurement apparatus 100 of FIG. 1, and shows a state of a cut surface when the measurement unit 10 is cut along a vertical plane. . The measurement unit 10 includes a housing 40 having a Z driving unit 41, an XY driving unit 42, imaging elements 43 and 44, a transmission illumination unit 50, a ring illumination unit 60, a coaxial incident illumination light source 71, and a light receiving lens unit 80. It is configured.

  The Z drive unit 41 is a Z position adjusting unit that moves the movable stage 12 in the Z axis direction based on a drive signal from the control unit 20 to adjust the position of the workpiece in the Z axis direction. The XY drive unit 42 is an XY position adjusting unit that adjusts the position of the workpiece in the XY plane by moving the movable stage 12 in the X-axis direction and the Y-axis direction based on the XY drive signal from the control unit 20.

  The transmitted illumination unit 50 is an illumination device for irradiating the work placed on the movable stage 12 with detection light from below, and includes a transmitted illumination light source 51, a mirror 52, and an optical lens 53. The detection light emitted from the transmission illumination light source 51 is reflected by the mirror 52 and emitted through the optical lens 52. The detection light passes through the movable stage 12, a part of the transmitted light is blocked by the work, and the other part enters the light receiving lens unit 80.

  The ring illumination unit 60 is an illumination device for irradiating the workpiece on the movable stage 12 with detection light from above, and includes a ring-shaped light source surrounding the light receiving lens unit 80. The coaxial epi-illumination light source 71 is a light source for irradiating the workpiece on the movable stage 12 with detection light from above, and the optical axis of the irradiation light to the workpiece and the optical axis of the reflected light from the workpiece are coaxial. Thus, the half mirror 72 is arranged. As a method for illuminating the workpiece, one of transmission illumination, ring illumination, and coaxial epi-illumination can be selectively switched.

  The light receiving lens unit 80 is an optical system including the light receiving lenses 81, 84, 86, the half mirror 82, and the diaphragm plates 83 and 85, and receives the transmitted light from the transmitted illumination unit 50 and the reflected light of the detection light by the work. Then, an image is formed on the image sensors 43 and 44. The light receiving lens 81 is an optical lens disposed on the movable stage 12 side, and is disposed to face the upper surface of the movable stage 12. The light receiving lens 84 is an optical lens disposed on the image sensor 43 side, and is disposed to face the image sensor 43. The light receiving lens 86 is an optical lens disposed on the image sensor 44 side, and is disposed to face the image sensor 44.

  The diaphragm plate 83 and the light receiving lens 84 are low-magnification-side image forming portions having a low photographing magnification, and are arranged such that their central axes coincide with the optical lens 53 and the light receiving lens 81. On the other hand, the diaphragm plate 85 and the light receiving lens 86 are high-magnification side imaging units with high photographing magnification, and detection light from the work is incident through the half mirror 82. The light receiving lenses 81, 84, and 86 have a property that does not change the size of the image even if the position of the workpiece in the optical axis direction (Z-axis direction) changes, and is called a telecentric lens.

  The image sensor 43 is a low-magnification image sensor that captures a low-magnification visual field formed by the light-receiving lens unit 80 and generates a low-magnification image. The image sensor 44 is a high-magnification image sensor that captures a high-magnification field-of-view workpiece formed by the light-receiving lens unit 80 at a high magnification and generates a high-magnification image. The high magnification field is a narrower field than the low magnification field, and is formed in the low magnification field.

  The imaging elements 43 and 44 are each composed of a semiconductor element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor).

  In this dimension measuring apparatus 100, as long as it is within the detection area 13 of the movable stage 12, a workpiece can be captured at a low magnification field of view no matter where it is placed. Further, the work placed in the low magnification field of view is guided into the high magnification field of view by photographing the low magnification image and moving the movable stage 12 in the XY plane, and is photographed at a high magnification. In this dimension measuring apparatus 100, the low magnification field and the high magnification field are substantially concentric, and a low magnification image and a high magnification image can be acquired simultaneously.

<Operation of image measuring apparatus>
Steps S101 to S103 in FIG. 3 are flowcharts showing an example of the operation of the image measurement apparatus 100 in FIG. In this image measuring apparatus 100, the operation consists of three processes, namely, creation of measurement setting data (step S101), execution of measurement (step S102), and display of measurement results (step S103).

  The measurement setting data is information necessary for execution of measurement, and includes feature amount information indicating feature amounts, information indicating measurement locations and measurement types, information indicating design values and tolerances for each measurement location, and the like. The feature amount information is positioning information for analyzing the workpiece image and detecting the position and posture of the workpiece, and is set based on predetermined master data. If the feature amount information, the information indicating the measurement location and the measurement type are set based on the high-magnification image, identification information indicating that fact is stored as measurement setting data.

  The measurement setting data is created in the control unit 20. Alternatively, the configuration may be such that measurement setting data created in an information processing terminal such as a PC (personal computer) is transferred to the control unit 20 and used. The measurement process is executed based on such measurement setting data. And the display process of a measurement result is performed by displaying the dimension value etc. which were obtained by measurement on the display 11. FIG.

<Create measurement setting data>
Steps S201 to S203 in FIG. 4 are flowcharts showing an example of the operation when creating the measurement setting data in the image measurement apparatus 100 in FIG. This figure shows a case where measurement setting data is created in the control unit 20.

  The measurement setting data creation process includes three processing procedures: design data input (step S201), feature value setting (step S202), and design value and tolerance correction (step S203). In the design data input step, a captured image obtained by photographing a predetermined reference object such as a master piece or CAD data created by CAD is input, and contour information for contour comparison to be described later is acquired from the input design data. It is a step to do. The contour information is a set of edge points of an image obtained by photographing the master piece as design data. When CAD data is used as design data, the design value of the CAD data corresponds to the contour information. .

  When tolerances are set in advance in the input design data for the range in which contour comparison is performed and for each contour to be compared, these pieces of information are also input together with the design data and set as measurement setting data.

  In step S202, the feature amount is automatically extracted from the input design data. However, the feature amount may be set by setting a range in which the user extracts the feature amount.

  Subsequently, in step S203, the user can correct the range or tolerance for performing the contour comparison as necessary. By executing the above steps, the measurement setting data including the contour comparison range of the design data, the contour information within the contour comparison range as the design value, and the tolerance of each contour position is generated and stored.

<Contour comparison>
Steps S301 to S308 in FIG. 5 are flowcharts illustrating an example of an operation at the time of measurement in the image measurement apparatus 100 in FIG. First, the work placed on the movable stage 12 is photographed to obtain a work image, and the work image is analyzed based on the feature amount information of the measurement setting data, thereby positioning the work (step S301).

  The positioning of the workpiece is performed by detecting the position and orientation of the workpiece in the workpiece image using a method such as pattern matching based on the feature amount information. For example, the alignment between the work image and the design data is performed by a method using a normalized correlation search or by simply matching the reference coordinates with the design data.

  Next, based on the detection result of the position and orientation and the measurement setting data, a range for contour comparison is specified (step S302), and an edge existing in the comparison range is extracted (step S303). As an edge extraction method, a method using the luminance value of the image, a method using the first derivative of the luminance value, a method using the second derivative of the luminance value, or the like can be used.

  Here, the case where edge extraction is performed after the workpiece is positioned has been described, but a configuration in which alignment between the workpiece image and the design data is performed using the edge point extracted from the workpiece image may be employed. As an alignment method using edge points, a method based on generalized Hough transform, geometric hashing, a method based on geometric correlation search, or the like can be used.

  Next, each extracted edge position is compared with the outline information (design value) of the design data corresponding to each edge position, and an error is calculated (steps S304 and S305). The error from the design value is calculated geometrically. That is, when the contour information of the design data is given as a curve, the error can be defined as the distance between the edge position and the normal direction of the curve. Further, when the contour information is given as reference coordinates, it can be calculated as a distance in the direction of each coordinate axis of XY.

  Subsequently, the error calculated at this time is compared with the tolerance included in the measurement setting data (step S306), and pass / fail is determined for each edge position (step S307). In this way, by comparing the contour information of the design data inputted in advance with the edge position extracted from the work image, an error from the design data can be calculated for each edge position. In this embodiment, the error from the design data is calculated for each edge position, but the error may be calculated only for a part of the edge positions by thinning out the edge positions.

<Display of pass / fail judgment results>
Steps S401 to S404 in FIG. 6 are flowcharts showing an example of the operation when displaying the pass / fail judgment result in the image measuring apparatus 100 in FIG. When the measurement for the plurality of workpieces shown in the flowchart of FIG. 5 is completed, processing for displaying the edges extracted from the workpiece image and the result of the error determination for each edge position on the workpiece image as measurement results is started. .

  First, it is determined whether or not there is an edge position that is determined to be defective due to the error being outside the tolerance range. If there is, the error at the edge position at which the error magnitude (absolute value) is maximized is numerically determined. Displayed (steps S401 and S402). At this time, the error of the edge position to be displayed is the error of the edge position where the magnitude of the error is the maximum in a predetermined section on the edge including the area where the error is outside the tolerance range. Is displayed as a representative value.

  Next, the edge extracted from the workpiece image is displayed using a predetermined shape line indicating the contour shape of the workpiece (step S403). This shape line is displayed in a display mode capable of identifying whether the error is within the tolerance range or outside the tolerance range. Specifically, the shape line whose edge position error is within the tolerance range and the shape line outside the tolerance range are displayed in different colors. For example, a shape line whose error is within the tolerance range is displayed in green, and a shape line outside the tolerance range is displayed in red.

  Next, a tolerance range including the contour position of the design data is displayed on the work image (step S404). It should be noted that the display mode of the contour position and tolerance range only needs to be identifiable. Further, the order in which the processing procedures from step S402 to step S404 are executed is arbitrary.

  FIG. 7 is a diagram showing an example of an operation at the time of displaying the pass / fail judgment result in the image measuring apparatus 100 of FIG. 1, and shows a workpiece image 1 that captures the state of the entire workpiece. This figure shows a work image 1 obtained by photographing a work in a low-magnification visual field at a low magnification. This work consists of a thin flat plate-like member having a complicated contour shape. The work image 1 is a photographed image photographed during the transmission illumination.

  The result of the error quality determination is displayed on such a work image 1. That is, the shape line 2 indicating the edge extracted from the work image 1 is superimposed on the work image 1, and the good section on the edge where the error is within the tolerance range and the defective section where the error is outside the tolerance range are identified. In order to make it possible, the shape line 2 is displayed in different colors.

  In this example, the section from the edge position A1 to the edge position A2 is a defective section in which the error is outside the tolerance range, and the error at the edge position where the magnitude of the error is maximum in the defective section is displayed numerically. . Specifically, the error defective section is subdivided into a plurality of determination sections having a fixed section length, and for each determination section, the error at the edge position where the magnitude of the error is maximum in the determination section is displayed numerically. .

  Here, two edge positions where the error is maximum are extracted, and numerical values “0.742” and “0.651” indicating the measured error values (maximum values) are displayed in association with the edge positions. Yes. A section other than the defective section from the edge position A1 to the edge position A2 is a good section where the error is within the tolerance range.

  FIG. 8 is a diagram illustrating an example of an operation at the time of displaying the pass / fail determination result in the image measurement apparatus 100 of FIG. 1, and shows a work image 1 that captures a part of the work of FIG. 7. This figure shows a workpiece image 1 obtained by shooting a workpiece in a high-magnification visual field at a high magnification.

  In this work image 1, in the defective section from the edge position A1 to the edge position A2, the tolerance range including the contour position of the design data in addition to the measured value 5 of the error of the edge position where the error is maximum is the contour line 3, Displayed using tolerance lines 4a and 4b.

  The contour line 3 indicates the contour position (design value). Moreover, one tolerance line 4a is a line (figure) indicating the upper limit value of the tolerance, and the other tolerance line 4b is a line indicating the lower limit value of the tolerance. The amount of displacement in the normal direction of the contour 3 from the position on the contour 3 is defined as an error of the edge position. In this example, a tolerance zone indicating a region within the tolerance range is formed along the contour line 3 and displayed so as to be distinguishable from the workpiece and the shape line 2. Specifically, the tolerance zone is displayed in a color different from that of the workpiece or the shape line 2.

  In this way, by displaying the representative value of the error in the determination section as a numerical value, it is possible to easily identify the error of the edge position greatly deviating from the design value. In addition, since the shape line 2 indicating the edge extracted from the work image is displayed on the work image 1 together with the error quality determination result, the error can be identified along the edge position of the work, and the work image 1 Can be easily grasped. Therefore, it is possible to easily determine whether the workpiece is actually deformed or whether the edge point is erroneously extracted.

  FIG. 9 is a diagram showing another example of the operation when displaying the pass / fail judgment result in the image measuring apparatus 100 of FIG. 1, in which the error of the edge position where the error is maximum is displayed in association with the edge position. The display mode is shown.

  In this figure, symbols “a” and “b” are added to the vicinity of the edge position for the two edge positions where the error is maximum in the defective section from the edge position A1 to the edge position A2, respectively. The corresponding error measurement values are listed as identification information. Such a list of measurement values of error may be displayed on the work image 1 or may be displayed separately from the work image 1.

<Control unit>
FIG. 10 is a block diagram illustrating a configuration example of the control unit 20 in the image measurement apparatus 100 of FIG. 1, and illustrates an example of a functional configuration in the control unit 20. The control unit 20 includes a measurement setting data storage unit 21, a work image storage unit 23, an edge extraction unit 24, an error calculation unit 25, an error determination unit 26, a measurement result display unit 27, and a connected image generation unit 28.

  The measurement setting data storage unit 21 holds measurement setting data including the contour information of the workpiece and the tolerance of the contour position. The work image storage unit 23 holds a captured image or a work image acquired from the measurement unit 10. The edge extraction unit 24 extracts edges from the work image.

  The error calculation unit 25 aligns the workpiece image and the contour information of the measurement setting data, calculates an error indicating the amount of displacement between the edge position on the workpiece image and the contour position corresponding to the edge position, and the error determination unit. 26. The error determination unit 26 compares the error calculated by the error calculation unit 25 with the tolerance of the corresponding measurement setting data, and performs pass / fail determination.

  The measurement result display unit 27 displays the edge extracted by the edge extraction unit 24 and the result of the pass / fail determination by the error determination unit 26 on the work image, and the magnitude of the error for the edge position where the error is determined to be defective. Screen data for displaying numerically the error of the edge position where the length is maximum is generated and output to the measurement unit 10.

  Specifically, the error at the edge position where the magnitude of the error is maximum is displayed numerically in a predetermined determination section including a region where the error is outside the tolerance range. The judgment interval may be a subdivision of a defective error interval, or may be an equally divided whole circumference of the edge extracted from the workpiece image, regardless of whether the error is within the tolerance range. good.

  The section length of such a determination section may be arbitrarily specified by the user, or may be fixed. Or the structure which determines automatically the area length of a determination area from the periphery length and shape of an edge may be sufficient.

  In addition, when a large number of edge positions where the size of the error is maximized are extracted in the determination section, the edge to be displayed is improved in order to improve the visibility so that the error measurement value is not continuously displayed. The position may be narrowed down. For example, it is conceivable to narrow down to an edge position where the size of the error is maximal and the size of the error exceeds a predetermined threshold. Alternatively, in order to remove noise, the size of the error may be maximized, and it may be narrowed down to an edge position where the error is not too far from the surrounding edge positions. Alternatively, it is conceivable to narrow down to an edge position where the difference between the error is maximized and the error of the edge position where the error is minimized at the peripheral edge positions.

  The measurement result display unit 27 displays a tolerance range including the contour position on the work image. When the field of view is narrow with respect to the workpiece to be measured, the connected image generation unit 28 can identify the error of the edge position over a wide range of the workpiece without reducing the photographing magnification. Are connected to each other to generate one work image.

  According to the present embodiment, when an error pass / fail judgment result is displayed on the work image 1, the error at the edge position where the magnitude of the error is the maximum is the numerical value for the edge position where the error is judged to be defective. Since the error is displayed, it is possible to easily identify the error of the edge position greatly deviating from the design value among the edge positions where the error is outside the tolerance range. In addition, since the edge extracted from the work image 1 is displayed on the work image 1 together with the error pass / fail judgment result, the error can be identified along the edge position of the work and the correspondence with the work image is easy. Can grasp.

DESCRIPTION OF SYMBOLS 1 Work image 2 Shape line 3 Contour lines 4a and 4b Tolerance line 5 Error measurement value 10 Measurement unit 11 Display 11a Display screen 12 Movable stage 13 Detection area 14a XY position adjustment knob 14b Z position adjustment knob 15 Power switch 16 Measurement start switch 20 control unit 21 measurement setting data storage unit 23 work image storage unit 24 edge extraction unit 25 error calculation unit 26 error determination unit 27 measurement result display unit 28 connected image generation unit 31 keyboard 32 mouse 40 casing 41 Z drive unit 42 XY drive Sections 43 and 44 Image sensor 50 Transmission illumination unit 51 Transmission illumination light source 52 Mirror 53 Optical lens 60 Ring illumination unit 71 Coaxial incident illumination light source 72 Half mirror 80 Light reception lens units 81, 84, 86 Light reception lens 82 Half mirror 83, 85 Aperture plate 1 0 image measuring apparatus A1, A2 edge position

Claims (7)

In an image measuring apparatus for measuring a dimension of the workpiece by acquiring a workpiece image obtained by photographing the workpiece and detecting an edge in the workpiece image.
Edge extraction means for extracting edges from the workpiece image;
Measurement setting data storage means for holding measurement setting data including the contour information of the workpiece and the tolerance of the contour position;
Error calculation means for aligning the workpiece image and the contour information, and calculating an error indicating an amount of displacement between the edge position on the workpiece image and the contour position corresponding to the edge position;
An error determination means for comparing the calculated error with the tolerance and performing a pass / fail determination;
A measurement result display means for displaying the extracted edge and the result of the quality determination on the work image,
The image measurement apparatus characterized in that the measurement result display means numerically displays an error of an edge position where the magnitude of the error is maximum for an edge position where the error is determined to be defective.   2. The measurement result display means numerically displays an error at an edge position where the magnitude of the error is maximum in a certain section including a region where the error is outside a tolerance range. Image measuring device.   The image measurement apparatus according to claim 2, wherein the measurement result display unit displays a numerical value of an error in association with an edge position where the magnitude of the error is maximum.   The image measurement apparatus according to claim 3, wherein the measurement result display unit displays a tolerance range including the contour position on the work image.   The connected image generating means for connecting two or more photographed images in which different parts of the same work are respectively photographed to generate one work image is provided. Image measuring device. In an image measurement method for measuring a dimension of the workpiece by acquiring a workpiece image obtained by photographing the workpiece and detecting an edge in the workpiece image,
An edge extraction step of extracting an edge from the workpiece image;
A measurement setting data storage step for storing measurement setting data including the contour information of the workpiece and the tolerance of the contour position;
An error calculating step of aligning the workpiece image and the contour information, and calculating an error indicating an amount of displacement between the edge position on the workpiece image and the contour position corresponding to the edge position;
An error determination step for comparing the calculated error with the tolerance and performing a pass / fail determination;
Measurement that displays the extracted edge and the result of the pass / fail judgment on the work image and numerically displays the error of the edge position at which the magnitude of the error becomes the maximum for the edge position where the error is judged to be defective. An image measurement method comprising: a result display step. In a program for an image measuring device for measuring a dimension of the workpiece by acquiring a workpiece image obtained by photographing the workpiece and detecting an edge in the workpiece image,
An edge extraction procedure for extracting an edge from the workpiece image;
A measurement setting data storage procedure for storing measurement setting data including the contour information of the workpiece and the tolerance of the contour position;
An error calculation procedure for aligning the workpiece image and the contour information, and calculating an error indicating an amount of displacement between the edge position on the workpiece image and the contour position corresponding to the edge position;
An error determination procedure for comparing the calculated error with the tolerance and performing a pass / fail determination;
Measurement that displays the extracted edge and the result of the pass / fail judgment on the work image and numerically displays the error of the edge position at which the magnitude of the error becomes the maximum for the edge position where the error is judged to be defective. A program for an image measuring apparatus, characterized in that a result display procedure is executed.

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